Method of making containers



Jan. 25, 1938. H. DEBOR 2,106,496

' METHOD OF MAKING CONTAINERS Original Filed May 51, 1950 Patented Jan. 25, 1938 UNITED STATES METHOD or mama commas Hermann Debor, Munich, Germany, assignor to Dominion Oxygen Company, Limited, a corporation of Canada.

Original application May 31, 1930, Serial No. 458,435. Divided and this application July 27,

1933, Serial N0. 682,525.

Renewed July 8, 1937.

In Germany October 12, 1929 15 Claims (01. 29-1482) The present invention relates to methods of making vessels or containers such as steel flasks. steam boilers, and the like, which are adapted to withstand high pressures.

The present application is a division of U. S. patent application Serial Number 458,435 filed May 31, 1930 by Hermann Debor, which is directed to hollow vessels or containers for high pressures. Objects of this invention are to provide manufacturing methods adapted to increase the capacity of containers or pressure vessels without increasing their weight and/or to decrease their weight without decreasing their capacity.

In accordance with this invention these objects may be accomplished, in one embodiment, by subjecting a cylindrical metallic blank or shell (of suitable sheet metal) to a suitable contracting or constricting force, at properly spaced intervals, or by surrounding it with suitable tight collars or frets, at intervals, whereupon the volume of the portions intermediate the constrictions or collars is enlarged by causing these portions to assume a dome-shaped or spheroidal shape, for' example, by internally applying a fluid expanding medium under high pressure. This dilatation results in an increase in capacity of the container, a reduction in the wall thickness of the spheroids, and a consequent reduction in the weight per unit of volume of the completed container.

Alternatively, a multi-spherical cylindrical container of increased capacity and increased resistance to internal pressures may be-produced, and the use of the above-mentioned collars or necks around the constricted portions may be avoided, by casting metal into a suitable mold which is patterned or shaped in such a manner that there results a concentration or excess of metallic material at the peripheral intersections of the spherical zones, that is, an enlargement of the wall thickness of the container at the peripheral intersections or necks between the spherical zones. If desired, a container thus obtained may have its spheroids further expanded and/or its cross-section further reduced at the points of constriction.

In the various embodiments of this invention, the relative internal dimensions of the spherical zones and of the constrictions between said zones may preferably be such that the radius of the spherical zones has a numerical value which is intermediate the radius and the diameter of the constrictions. 1

The several types of containers thus obtained ,55 may be subjected to a heat treatment for the purpose of normalizing the crystal structure of the metallic shell.

The invention may be better understood by referring to the accompanying drawing which shows various modifications thereof. 5

Fig. 1 shows one particular form 01' a highpressure vessel; I I

Figure 2 shows another form of a high pressure container, partly in longitudinal section;

Figure 3 represents a third form, partly in lon- 1o gitudinal section;

Figure 4 shows a longitudinal axial section of another embodiment of a pressure vessel.

The embodiment of the invention shown in Fig.

1 comprises a cylindrical hollow metal body I0, 15 closed at its ends, which is constricted at uniform intervals II and whose volume is enlarged by expanding the zones between the strictures to a substantially spherical shape. Pressureresisting reinforcing rings I, which may prefer- 2o ably have a triangular shape in cross-section, are placed circumferentially. around the strictures prior or subsequent to the expanding operation, for the purpose of compensating for any exces- I sive stresses and strains to which the strictures 25 may be subjected when the container is in service. Preferably these rings or collars are applied in i such a manner that the apex of the triangle makes contact with the outer surface of the container in the groove of the constriction. 30

Figure 2 shows a view, partly in longitudinal axial section, of a hollow vessel or container which has been made by the casting of metal into a suitably shaped mold. In this method. of manufacture, the constricted portions or necks 2 l are 35 reinforced by the provision of a surplusof cast metal around the circumference of the necks, in order to avoid the use of the special pressureresisting rings shown at f in Fig. 1.

Figure 3 represents a view-partly in longitudi- 40 nal axial section, of a hollow; cylinder or container in course of fabrication in accordance with a modification of the process ofmanufacture shown in Fig. 1. The original inner diameter D of the cylindrical blank is shown by the vertical 45 distance between the solid horizontal lines as shown. At suitable intervals this diameter is reduced by compression, whereby the cylindrical blank assumes the necked or constricted shape shown in full lines. In order to increase the 50 capacity of the hollow spheroids thus formed, the zones intermediate the strictures may subsequently have their volume enlarged by outward expansion, whereupon they assume the shape shown by the dotted lines. To facilitate this envessel or container shown in this figure may be" formed, for example, by placing a metal cylinder,

such as shown by the dotted lines a, in a suitable die or matrix, and by internally applying high pressure such as fluid pressure. A container thus produced comprises several spherical zones bl, b2, b3 and bl the walls of which are dome-shaped in cross-section; these spherical zones or spheroids are integrally united to the adjoining zones in the planes of the constrictions. In this embodiment of the invention the diameter c of the constrictions (1. e. the circular planes of intersection of the spherical zones bi to M) is substantially equal to the inner diameter of the-original cylinder 0, and also equal to the axial length d of a spherical zone (i. e. equal to the distance between successive planes of intersection). The diameter e of each zone hi to M thus forms the hypothenuse of a right isosceles triangle having catheti or sides 0 and d.

' To complete the several containers, the end zones may be suitably closed, as illustrated.

I claim:

1. The method of making a metallic container adapted to withstand internal pressures, said container consisting of a plurality of metallic spheroidal hollow bodies in intersecting relation, the wall thickness of said container being enlarged at the peripheral intersections, and the major axes of the planes of intersection of said bodies being considerably less than the greatest internal diameter'of said bodies, whereby the surface of said spheroidal bodies tends to approximate that of a sphere, which method includes the step of casting metal into a suitable mold which is shaped in such a manner that there results a concentration of metallic material at the peripheral intersections of said hollow bodies, whereby the resistance of the peripheral intersections tothe effects of internal pressure is caused to substantially approximate the resistance inherent in the spheroidal portions. I

2. The method of fabricating an elongated pressure vessel which comprises pressing a metal tube into a series of interconnected and intercommunicating hollow spheroids having the centers of curvature of all elements thereof located in the main longitudinal axis of said tube.

3. The method of making a container adapted to withstand high pressure, which comprises circumferentialiy and radially constricting a tubular metal shell at intervals lengthwise thereof, the diameter of each constriction so formed being not substantially greater than the distance between any two'successive constrictions; and expanding to spheroidal form the portions of said shell between such constrictions, thereby providing a pressure container comprising a series of interconnected and intercommunicating hollow spheroids having the centers of all points thereof located in the main longitudinal axis of said container.

'cumferentially and radially constricting a tubular metal shell at intervals lengthwise thereof, the diameter of each constriction so formed being not substantially greater than the'distance' between any two successive constrictions; and applying fluid pressure internally to such shell to expand the portions of said shell between said constrictions to the form of spheroids having their centers located in the main longitudinal axis of said shell, thereby providing a pressure container comprising a series of interconnected and intercommunicating hollow spheroids.

5. The method of making a container adapted to withstand high pressure, which comprises circumferentialiy and radially constricting a tubular metal shell at intervals lengthwise thereof, the diameter of each constriction so formed being not substantially greater than the distance between any two successive constrictions; reinforcing the walls of the shell at the constricted zones; and expanding to spheroidal form the portions of said shell between such constrictions, thereby provid- 6. A method of making a container adapted to withstand high internal pressure, which comprises forming a series of interconnected hollow spheroidal zones of metal along a common axis while disposing the center of curvature of every element of each zone in said ads.

'7. A method of. making a container adapted to withstand high internal pressure. which comprises forming a series of hollow spheroidal zones along a common axis, integrally uniting successive zones by constrictions having a diiTrneten larger than the radius of said zones, and disposing the centers of said constrictions and the center of curvature of every element of each zone in said common axis.

8. A method of making a container as claimed in claim '7, including the step of reinforcing said constrictions.

,9. A method of making a container adapted to withstand high internal pressure, which comprises radially and circumferentialiy constricting an elongated hollow metal shell at intervals lengthwise thereof, and expanding the portions of said shell betweensuch constrictions to form hollow spheroidal zones having the centers of curvature of all elements thereof located in the main longitudinal axis of said shell.

10. A method of making a container as claimed in claim 9, and providing hollow spheroidal portions to close the opposite ends of said shell.

11. A method of making a container as claimed in claim 9, including the step of circumferentialiy reinforcing said constrictions.

12. A method of making a container as claimed in claim 9, in which the internal diameter of each constriction is greater than the distance between the planes of any two successive constrictions.

13. A method of making a container as claimed in claim 9, in which the container is subjected to heat treatment subsequent to the forming operation, for the purpose of normalizing its crystalspaced intervals along a hollow substantially cyportions of said shell between such constrictions to form hollow spheroidal zones having the centers of curvature of all elements thereof located in the main longitudinal axis of said shell.

15. A method of making a container adapted to withstand high internal pressure, which comprises disposing constricting and reinforcing metal rings circumterentially about and at lindrical metal shell, and expanding the portions of said shell between said rings until such portions formhollow spheroidal zones having the centers of curvature of all elements thereof located in the main longitudinal axis of said shell.

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